Shows last image, not first?

Hey!

First I need to mention, my blog images were all linked to Flickr so I used “Image Teleporter” to import the images to my blog:
http://wordpress.org/plugins/image-teleporter/

Now, I want to set the first image as my Featured Image but it keeps showing the last one 🙁
What could be the reason?

Thanks

https://wordpress.org/plugins/autoset-featured-image/